Fall protection systems, or fall arrest systems, are commonly used in industry to prevent accidents involving falls from elevated work environments, like rooftops. Workers wear a harness that is attached to a support assembly by means of a cable known as a lanyard or “lifeline.” Should a worker accidentally go over the edge of an elevated surface wearing such a harness, the lifeline will suspend the worker from the support assembly, preventing a fall to the ground below.
Common fall protection systems include rail assemblies and cable assemblies, in which a trolley or anchor is arranged for movement along a horizontal rail or cable which is supported above the elevated structure on which work is being performed. This arrangement provides protection from a substantial vertical fall while allowing the worker the freedom to move around the elevated surface.
U.S. Pat. No. 6,269,904 discloses a rail assembly having an I-beam supported on the bottom of a truss member which is mounted between support members over the elevated surface being worked on. A trolley is provided with wheels arranged to engage an upper side of the bottom flange of the I-beam such that the trolley can move along the I-beam in response to movement of the attached worker.
U.S. Pat. No. 6,334,507 discloses a cable assembly having parallel and generally horizontal anchoring lines spaced apart above the elevated surface. A trolley is provided with rollers arranged to allow movement along the longitudinal anchoring lines.
U.S. Pat. No. 6,478,112 discloses a rail and anchor system in which a sliding anchor comprises two members, one for each side of a crowned rail, each having a rail engaging portion and a connector portion. A hook at the end of the lanyard serves to both connect the two members of the anchor and secure the worker to the anchor by means of aligned openings in the connector portions of the anchor members. The engagement portions of the members are shaped to form a cavity that envelopes the crown of the rail when the members are connected.
The truss and cable supported systems of U.S. Pat. Nos. 6,269,904 and 6,334,507 respectively are designed to be supported in a specific orientation for loading in a predetermined direction. They are arranged to handle downward forces by means of an overhead support assembly. While the rail and anchor system provides for loading in a transverse direction, it lacks the smooth rolling motion of a trolley based system. In each case, the system is intended for a particular mounting arrangement that may be ideal for one use, but not another. As a result, there is a need for a fall protection system that can handle loading in multiple directions such that it can be mounted in a number of different orientations in order to be versatile enough to use for different applications.